Bellows-operating mechanism for player-pianos.



A. JAMESON.

BELLOWS OPERATING MECHANISM FOR PLAYER PIANOS. v

- APPLlCATlON FILED APR 9,l9l5.

1,168,264. Patented Jan ll, 1916.

2 SHEETS-SHEET 1.

WITNESSES: IN VEN TOR THEVCOLUMBIA PLANOGRAPl-l 50., WASHlNG'i'ON. n. c.

v A. JAMESON. BELLOWS OPERATING MECHANISM FOR PLAYER PIANOS.

APPLICATION FILED ARR-9,1915- n0 1 H H Um n1 as Tom E M t2 D W a D1 r Mai? THE COLUMBIA PLANOGRAPH (20.. WASHINGTON. D. C.

UNITED STATES PATENT OFFICE.

ALEXANDER JAMESON, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO EMERSON PIANO COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF ILLINOIS.

BELLOWS-OPERATING MECHANISM son PLAYER-runes.

To all whom it may concern:

Be it known that I, ALEXANDER J MEsoN,

A a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented a new and useful Bellows-Operating Mechanism for Player-Pianos, of which the following is a specification.

In the ordinary player piano and piano player, equal angular movements of the bellows pedals at ditferent'parts of their range produce very unequal movements of the bellows, the bellows movement decreasing in proportion to the pedal movement as the pedals approach the lower end of their range. This has many disadvantages, among which are the difficulty of playing pianissimo passages evenly by producing a light but steady vacuum and the difference in the accenting obtained by a sudden sharp pedal movement when the pedal is at different parts of its movement.

It is the object of my present invention '1 to make the relation between the pedal movement and the resultant bellows movement a substantially uniform one, so that at allparts of the range of pedal movement a definite angular movement of the pedals always produces substantially the same bellows movement; and to do this without interfering with the folding up of the bel- Iows pedals and their supports into the case.

In accomplishing this object I interconnect each pedal and its associated bellows by two links pivoted together at their adjacent ends and to the pedal and bellows respectively at their remote ends, and constrain thejoining ends of such links to travel in a curve'which produces a change in the angle between the two llnks as the pedal is moved so that the effective length of connecting rod (formed by the two links together) between the pedal and bellows is varied to compensate for the aforesaid varying relationship between pedal and bellows movements; and I locate the joint between such two links'so that they may swing rela tively to each other to permit the pedals to be folded into the case.

The accompanying drawing illustrates my invention. A

Figure 1 is a fragmentary front elevation of the lower part of a player piano embodying myv invention, some of the parts being broken away; Fig. 2 is a partialver- Specification of Letters Patent.

tical cross section through the lower part of such piano player, showingthe relationship of the various parts'with' the pedals raised and the bellows collapsed; and Fig. 3 is a somewhat enlarged view, showing some of the same parts as in Fig. 2, but with the bellows distended.

The bellows 10 are located in their usual position just above the floor 11 of the piano or player and behind the rail 12; and each bellows, only one being shown, comprises the usual fixed plate 13 and movable or swinging plate 1 1 connected by a folding wall 15 of leather or other suitable material. A link 16 is pivoted at one end by a pivot pin 17 to the movable plate 1 1 of each bellows and at the other end by a pivot pin 18 to one end of a link 19, which is curved to fit over. the rail 12 and has its other end pivoted by a pin 20 to a lug 21 on the under side of the associated pedal 22. The pedals, of which only one is shown, are pivoted on the usual frame 23, supported by a pair of links 2 1 and 25 pivotally connected to the frame 23 and to the fixed plates 13 of the bellows or other fixed part of the piano or player so that the frame and pedals may be swung to either the full line or the dotted line position shown in Fig. 2. When in full line position the rubber shod legs 26 of the pedal frame 23 rest on the floor and help support the frame. The pivot pins 18 are so located, by reason of the relation of the lengths of the arms 16 and 19, that the links 19 also swing with the frame and pedals to either full or dotted line position.

The two links 16 and 19 together form a jointed connecting rod, or a rod of varying effective length (measured by the distance between the pins 17 andQO) as the links move relatively to each other about the pin 18. If now the pin 18 is constrained to move properly, the effective length of the jointed connecting rod may be made to vary to produce proportionate angular movements of the pedal and the bellows throughout the whole range of pedal movement. In order to determine this path of movement for the pin 18, 1 divide the whole range aZ of movement of the pin 20 (and pedal 22) into any number of equal steps b, 0, cl, etc., and similarly divide the whole range aZ of movement'of the pin 17 (and movable plate 14:) into a corresponding number of'equ'al steps b, c, cl,etc., and from the vari- V Patented Jan. 11, 1916.

Application filed April 9, 1915., Serial No. 20,152.

ous pairs of corresponding points I), 0,'(Z, etc., on the two ranges I strike a series of intersecting arcs s and t, on radii equal to the effective lengths of the links 16 and 19 respectively, the various intersecting points u of which arcs determine the curve which the pin 18 should travel. IVhile the pin 18 can be made to travel this ideal curve, I have found that such curve is very closely and entirely sufli ciently approximated by the curve w, which consists of two smoothly connected arcs of circles drawn about the centers as and 3 and I cause the pin 18 to travel along the curve to by mounting on a pin at the point a: one end of a link 31 equal in effective length (between pivotal centers) to the distance between the points ac and 3 and connecting by a pin 32 to the other end of the link 31 a link 33 equal in effective length to the radius of that part of the curve to which is an are about the point 3 the other end of the link 33 being pivoted on the pin 18. The clockwise movement of the link 31 is suitably stopped when the pin 32 reaches the point 1, as by engaging the stationary plate 13.

With this arrangement, the downward movement of the pedal 22 exerts thrust on the links 16 and 19, and because the pin 18 is below the line joining the pins 17 and 20 also exerts tension on the links 31 and 33, so that these latter links tend to aline with each other. In consequence, as the pedal 22 is moved downward the pin 18 travels first in the arc of a circle around the pin 30 as a center and with a radius of the combined length of the links 31 and 33, until the pin 32 reaches the point y,- and then, continued movement of the link 31 being prevented as aforesaid, in the arc of a circle around the pin 32 (at the point with a radius of the link 33 only-in other words, the pin 18 travels in the curve to. This causes a relative swinging between the links 16 and 19 to vary their effective combined length to make the bellows movement substantially proportional to the pedal movement. When the down stroke of the pedal is completed, the pedal and bellows are suitably returned to normal position, as by a spring 35 bearing on the movable plate 14- of the bellows.

In order to equalize the action of the various links, and prevent binding, some of the links may be either doubled or bifurcated, so as to make a symmetrical struc ture. This is apparent from Fig. 1, which shows the link 16 bifurcated where it joins the link 19 and the links 31 and 33 doubled, there being one of each of these latter links on each side of the plane of the links 16 and 19. This construction also facilitates the folding in of the pedals.

Copies of this patent may be obtained for I claim as my invention: 1. In a mechanically operated musical 1nstrument, the combination of a bellows. a

pedal, a link pivoted to the pedal, :1.

link pivoted to the bellows, said two links being pivoted together, a third link pivoted to a fixed point and having a limited movement, and a fourth link pivoted to the third link and to the junction of the first two links.

2. In a mechanically operated musical instrument, the combination of a bellows, a pedal, a link pivoted to the pedal, a link pivoted to the bellows, said two links being pivoted together, and means for causing the pivotal connecting point between said two links to travel in a curve of variable curvature as the pedal is moved.

3. In a mechanically operated musical instrument, the combination of a bellows, a pedal, a link pivoted to the pedal, a link pivoted to the bellows, said two links being pivoted together, and means for guiding the pivotal connecting point between said two links in a curve which causes the movements of the pedal and bellows to be substantially proportional throughout their range of movement.

I. In a mechanically operated musical instrument, the combination of a bellows, a pedal, a connecting rod of variable effective length connecting said bellows and said pedal, and means for varying such effective length as the pedal is moved for causing the movements of the pedal and bellows to be substantially proportional throughout their range of movement.

5. In a mechanically operated musical instrument, the combination of a bellows, a pedal, a link pivoted to the pedal, a link pivoted to the bellows, said two links being pivoted together, means for causing the pivotal connecting point between said two links to travel in a curve of variable curvature as the pedal is moved, and a folding support for said pedal, said first link swinging about its pivotal connection with the second as the folding support for the pedal is folded.

6. In a mechanically operated musical instrument, the combination of a bellows, a pedal, a link pivoted to the pedal, a link pivoted to the bellows, said two links being pivoted together, and a linked support for the pivotal connection between said two links, said linked support comprising a plurality of links pivotally connected.

In witness whereof, I have hereunto set my hand at Indianapolis, Indiana, this sixth day of April, A. I). one thousand nine hundred and fourteen.

ALEXANDER JAllIESON.

five cents each, by addressing the Commissioner of Patents. Washington, D. C." 

